Weird—it seems that our birthday ritual of breathing all over a sheet cake and then feeding it to our dearest friends might not be totally sanitary.

Business Insider picks up some research suggesting that “the mere act of extinguishing those flickering lights multiplied the bacteria on the cake by 1,400%.” Oops! How they arrived at this revolting conclusion:

For the study, published this summer in the Journal of Food Research, a group of food scientists prepared two test birthday “cakes” made of Styrofoam which they then spread with real icing (vanilla, in case you were wondering) and decorated with exactly 17 candles. Before having volunteers blow out the candles on both cakes, they had all of them smell and consume a piece of hot pizza — “to simulate a meal-dessert sequence.” Afterwards, they compared the amount of bacteria present on each cake surface, and then repeated the whole exercise three times — because science.

“I personally will be aware of the health status of the blower and won’t blow out candles if I’m sick,” said Clemson professor Paul Dawson, the study’s leading author. But what better way to celebrate our loved ones than by consuming icing and fluffy yellow cake christened with their microbiome?